Engineered leucine decarboxylases

Abstract

The present invention provides engineered leucine decarboxylase (LDC) polypeptides and compositions thereof, as well as polynucleotides encoding the engineered leucine decarboxylase (LDC) polypeptides. In some embodiments, the engineered LDC polypeptides are optimized to provide enhanced catalytic activity, as well as reduced sensitivity to proteolysis, and/or increased tolerance to low pH environments. In some embodiments, the engineered LDC polypeptides are optimized to provide improved storage stability. The present invention also provides methods for the use of the compositions comprising the engineered LDC polypeptides for therapeutic and industrial purposes.

We claim: 
     
       1. An engineered leucine decarboxylase polypeptide comprising an amino acid sequence having at least 90%, 91%, 92,%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or more sequence identity to the entire sequence set forth in SEQ ID NO: 12, wherein the amino acid positions of said amino acid sequence are numbered with reference to the amino acid sequence of SEQ ID NO: 12, and wherein said amino acid sequence comprises a substitution at position 364, selected from L364K and L364R. 
     
     
       2. The engineered leucine decarboxylase polypeptide of  claim 1 , wherein said engineered leucine decarboxylase polypeptide exhibits more activity on leucine than the leucine decarboxylase polypeptide set forth in SEQ ID NO: 12. 
     
     
       3. The engineered leucine decarboxylase polypeptide of  claim 1 , wherein said engineered leucine decarboxylase polypeptide is more resistant to proteolysis than the leucine decarboxylase polypeptide set forth in SEQ ID NO: 12. 
     
     
       4. The engineered leucine decarboxylase polypeptide of  claim 1 , wherein said engineered leucine decarboxylase polypeptide is more thermostable than the leucine decarboxylase polypeptide set forth in SEQ ID NO: 12. 
     
     
       5. The engineered leucine decarboxylase polypeptide of  claim 1 , wherein said engineered leucine decarboxylase polypeptide has been isolated from a recombinant expression host. 
     
     
       6. A composition comprising at least one engineered leucine decarboxylase polypeptide provided in  claim 1 .